M36-4 X 340mm 內六角螺絲 | 六角驅動 | 部分螺紋 | 等級12.9 合金鋼 熱處理黑氧化物

These bolts held the jig together perfectly under heavy load, and the thermal black oxide finish looks both professional and durable. The partially threaded design made alignment much easier than fully threaded screws I've used before.

The hex socket drive made tightening them into my jig frame effortless, even in a cramped spot. These M36 screws feel incredibly solid for the size, and the black oxide finish seems durable enough for heavy workshop use.

Needed these for a job fixture I was building, and the 340mm length was exactly right. The hex socket drive made tightening them in tight spots so much easier than a standard bolt.